6 git-rev-parse - Pick out and massage parameters
11 'git rev-parse' [ --option ] <args>...
16 Many git porcelainish commands take mixture of flags
17 (i.e. parameters that begin with a dash '-') and parameters
18 meant for the underlying 'git-rev-list' command they use internally
19 and flags and parameters for the other commands they use
20 downstream of 'git-rev-list'. This command is used to
21 distinguish between them.
27 Use 'git-rev-parse' in option parsing mode (see PARSEOPT section below).
30 Only meaningful in `--parseopt` mode. Tells the option parser to echo
31 out the first `--` met instead of skipping it.
34 Do not output flags and parameters not meant for
35 'git-rev-list' command.
38 Do not output flags and parameters meant for
39 'git-rev-list' command.
42 Do not output non-flag parameters.
45 Do not output flag parameters.
48 If there is no parameter given by the user, use `<arg>`
52 The parameter given must be usable as a single, valid
53 object name. Otherwise barf and abort.
57 Only meaningful in `--verify` mode. Do not output an error
58 message if the first argument is not a valid object name;
59 instead exit with non-zero status silently.
62 Usually the output is made one line per flag and
63 parameter. This option makes output a single line,
64 properly quoted for consumption by shell. Useful when
65 you expect your parameter to contain whitespaces and
66 newlines (e.g. when using pickaxe `-S` with
70 When showing object names, prefix them with '{caret}' and
71 strip '{caret}' prefix from the object names that already have
75 Usually the object names are output in SHA1 form (with
76 possible '{caret}' prefix); this option makes them output in a
77 form as close to the original input as possible.
79 --symbolic-full-name::
80 This is similar to \--symbolic, but it omits input that
81 are not refs (i.e. branch or tag names; or more
82 explicitly disambiguating "heads/master" form, when you
83 want to name the "master" branch when there is an
84 unfortunately named tag "master"), and show them as full
85 refnames (e.g. "refs/heads/master").
88 Show all refs found in `$GIT_DIR/refs`.
91 Show branch refs found in `$GIT_DIR/refs/heads`.
94 Show tag refs found in `$GIT_DIR/refs/tags`.
97 Show tag refs found in `$GIT_DIR/refs/remotes`.
100 When the command is invoked from a subdirectory, show the
101 path of the current directory relative to the top-level
105 When the command is invoked from a subdirectory, show the
106 path of the top-level directory relative to the current
107 directory (typically a sequence of "../", or an empty string).
110 Show `$GIT_DIR` if defined else show the path to the .git directory.
112 --is-inside-git-dir::
113 When the current working directory is below the repository
114 directory print "true", otherwise "false".
116 --is-inside-work-tree::
117 When the current working directory is inside the work tree of the
118 repository print "true", otherwise "false".
120 --is-bare-repository::
121 When the repository is bare print "true", otherwise "false".
125 Instead of outputting the full SHA1 values of object names try to
126 abbreviate them to a shorter unique name. When no length is specified
127 7 is used. The minimum length is 4.
131 Parse the date string, and output the corresponding
132 --max-age= parameter for 'git-rev-list'.
135 --before=datestring::
136 Parse the date string, and output the corresponding
137 --min-age= parameter for 'git-rev-list'.
140 Flags and parameters to be parsed.
146 A revision parameter typically, but not necessarily, names a
147 commit object. They use what is called an 'extended SHA1'
148 syntax. Here are various ways to spell object names. The
149 ones listed near the end of this list are to name trees and
150 blobs contained in a commit.
152 * The full SHA1 object name (40-byte hexadecimal string), or
153 a substring of such that is unique within the repository.
154 E.g. dae86e1950b1277e545cee180551750029cfe735 and dae86e both
155 name the same commit object if there are no other object in
156 your repository whose object name starts with dae86e.
158 * An output from 'git-describe'; i.e. a closest tag, followed by a
159 dash, a `g`, and an abbreviated object name.
161 * A symbolic ref name. E.g. 'master' typically means the commit
162 object referenced by $GIT_DIR/refs/heads/master. If you
163 happen to have both heads/master and tags/master, you can
164 explicitly say 'heads/master' to tell git which one you mean.
165 When ambiguous, a `<name>` is disambiguated by taking the
166 first match in the following rules:
168 . if `$GIT_DIR/<name>` exists, that is what you mean (this is usually
169 useful only for `HEAD`, `FETCH_HEAD`, `ORIG_HEAD` and `MERGE_HEAD`);
171 . otherwise, `$GIT_DIR/refs/<name>` if exists;
173 . otherwise, `$GIT_DIR/refs/tags/<name>` if exists;
175 . otherwise, `$GIT_DIR/refs/heads/<name>` if exists;
177 . otherwise, `$GIT_DIR/refs/remotes/<name>` if exists;
179 . otherwise, `$GIT_DIR/refs/remotes/<name>/HEAD` if exists.
181 HEAD names the commit your changes in the working tree is based on.
182 FETCH_HEAD records the branch you fetched from a remote repository
183 with your last 'git-fetch' invocation.
184 ORIG_HEAD is created by commands that moves your HEAD in a drastic
185 way, to record the position of the HEAD before their operation, so that
186 you can change the tip of the branch back to the state before you ran
188 MERGE_HEAD records the commit(s) you are merging into your branch
189 when you run 'git-merge'.
191 * A ref followed by the suffix '@' with a date specification
193 pair (e.g. '\{yesterday\}', '\{1 month 2 weeks 3 days 1 hour 1
194 second ago\}' or '\{1979-02-26 18:30:00\}') to specify the value
195 of the ref at a prior point in time. This suffix may only be
196 used immediately following a ref name and the ref must have an
197 existing log ($GIT_DIR/logs/<ref>). Note that this looks up the state
198 of your *local* ref at a given time; e.g., what was in your local
199 `master` branch last week. If you want to look at commits made during
200 certain times, see `--since` and `--until`.
202 * A ref followed by the suffix '@' with an ordinal specification
203 enclosed in a brace pair (e.g. '\{1\}', '\{15\}') to specify
204 the n-th prior value of that ref. For example 'master@\{1\}'
205 is the immediate prior value of 'master' while 'master@\{5\}'
206 is the 5th prior value of 'master'. This suffix may only be used
207 immediately following a ref name and the ref must have an existing
208 log ($GIT_DIR/logs/<ref>).
210 * You can use the '@' construct with an empty ref part to get at a
211 reflog of the current branch. For example, if you are on the
212 branch 'blabla', then '@\{1\}' means the same as 'blabla@\{1\}'.
214 * A suffix '{caret}' to a revision parameter means the first parent of
215 that commit object. '{caret}<n>' means the <n>th parent (i.e.
217 is equivalent to 'rev{caret}1'). As a special rule,
218 'rev{caret}0' means the commit itself and is used when 'rev' is the
219 object name of a tag object that refers to a commit object.
221 * A suffix '{tilde}<n>' to a revision parameter means the commit
222 object that is the <n>th generation grand-parent of the named
223 commit object, following only the first parent. I.e. rev~3 is
224 equivalent to rev{caret}{caret}{caret} which is equivalent to
225 rev{caret}1{caret}1{caret}1. See below for a illustration of
226 the usage of this form.
228 * A suffix '{caret}' followed by an object type name enclosed in
229 brace pair (e.g. `v0.99.8{caret}\{commit\}`) means the object
230 could be a tag, and dereference the tag recursively until an
231 object of that type is found or the object cannot be
232 dereferenced anymore (in which case, barf). `rev{caret}0`
233 introduced earlier is a short-hand for `rev{caret}\{commit\}`.
235 * A suffix '{caret}' followed by an empty brace pair
236 (e.g. `v0.99.8{caret}\{\}`) means the object could be a tag,
237 and dereference the tag recursively until a non-tag object is
240 * A colon, followed by a slash, followed by a text: this names
241 a commit whose commit message starts with the specified text.
242 This name returns the youngest matching commit which is
243 reachable from any ref. If the commit message starts with a
244 '!', you have to repeat that; the special sequence ':/!',
245 followed by something else than '!' is reserved for now.
247 * A suffix ':' followed by a path; this names the blob or tree
248 at the given path in the tree-ish object named by the part
251 * A colon, optionally followed by a stage number (0 to 3) and a
252 colon, followed by a path; this names a blob object in the
253 index at the given path. Missing stage number (and the colon
254 that follows it) names a stage 0 entry. During a merge, stage
255 1 is the common ancestor, stage 2 is the target branch's version
256 (typically the current branch), and stage 3 is the version from
257 the branch being merged.
259 Here is an illustration, by Jon Loeliger. Both commit nodes B
260 and C are parents of commit node A. Parent commits are ordered
263 ........................................
274 ........................................
279 D = A^^ = A^1^1 = A~2
282 G = A^^^ = A^1^1^1 = A~3
283 H = D^2 = B^^2 = A^^^2 = A~2^2
284 I = F^ = B^3^ = A^^3^
285 J = F^2 = B^3^2 = A^^3^2
291 History traversing commands such as 'git-log' operate on a set
292 of commits, not just a single commit. To these commands,
293 specifying a single revision with the notation described in the
294 previous section means the set of commits reachable from that
295 commit, following the commit ancestry chain.
297 To exclude commits reachable from a commit, a prefix `{caret}`
298 notation is used. E.g. "`{caret}r1 r2`" means commits reachable
299 from `r2` but exclude the ones reachable from `r1`.
301 This set operation appears so often that there is a shorthand
302 for it. When you have two commits `r1` and `r2` (named according
303 to the syntax explained in SPECIFYING REVISIONS above), you can ask
304 for commits that are reachable from r2 excluding those that are reachable
305 from r1 by "`{caret}r1 r2`" and it can be written as "`r1..r2`".
307 A similar notation "`r1\...r2`" is called symmetric difference
308 of `r1` and `r2` and is defined as
309 "`r1 r2 --not $(git merge-base --all r1 r2)`".
310 It is the set of commits that are reachable from either one of
311 `r1` or `r2` but not from both.
313 Two other shorthands for naming a set that is formed by a commit
314 and its parent commits exist. The `r1{caret}@` notation means all
315 parents of `r1`. `r1{caret}!` includes commit `r1` but excludes
318 Here are a handful of examples:
332 In `--parseopt` mode, 'git-rev-parse' helps massaging options to bring to shell
333 scripts the same facilities C builtins have. It works as an option normalizer
334 (e.g. splits single switches aggregate values), a bit like `getopt(1)` does.
336 It takes on the standard input the specification of the options to parse and
337 understand, and echoes on the standard output a line suitable for `sh(1)` `eval`
338 to replace the arguments with normalized ones. In case of error, it outputs
339 usage on the standard error stream, and exits with code 129.
344 'git-rev-parse --parseopt' input format is fully text based. It has two parts,
345 separated by a line that contains only `--`. The lines before the separator
346 (should be more than one) are used for the usage.
347 The lines after the separator describe the options.
349 Each line of options has this format:
352 <opt_spec><flags>* SP+ help LF
356 its format is the short option character, then the long option name
357 separated by a comma. Both parts are not required, though at least one
358 is necessary. `h,help`, `dry-run` and `f` are all three correct
362 `<flags>` are of `*`, `=`, `?` or `!`.
363 * Use `=` if the option takes an argument.
365 * Use `?` to mean that the option is optional (though its use is discouraged).
367 * Use `*` to mean that this option should not be listed in the usage
368 generated for the `-h` argument. It's shown for `--help-all` as
369 documented in linkgit:gitcli[7].
371 * Use `!` to not make the corresponding negated long option available.
373 The remainder of the line, after stripping the spaces, is used
374 as the help associated to the option.
376 Blank lines are ignored, and lines that don't match this specification are used
377 as option group headers (start the line with a space to create such
385 some-command [options] <args>...
387 some-command does foo and bar!
391 foo some nifty option --foo
392 bar= some cool option --bar with an argument
394 An option group Header
395 C? option C with an optional argument"
397 eval `echo "$OPTS_SPEC" | git rev-parse --parseopt -- "$@" || echo exit $?`
403 * Print the object name of the current commit:
406 $ git rev-parse --verify HEAD
409 * Print the commit object name from the revision in the $REV shell variable:
412 $ git rev-parse --verify $REV
415 This will error out if $REV is empty or not a valid revision.
420 $ git rev-parse --default master --verify $REV
423 but if $REV is empty, the commit object name from master will be printed.
428 Written by Linus Torvalds <torvalds@osdl.org> .
429 Junio C Hamano <junkio@cox.net> and Pierre Habouzit <madcoder@debian.org>
433 Documentation by Junio C Hamano and the git-list <git@vger.kernel.org>.
437 Part of the linkgit:git[1] suite